We specialize in 20# seamless pipes and square tubes, 45# seamless pipes and square tubes, Q345b seamless pipes and rectangular tubes, Q345d seamless square pipes, Q235b rectangular tubes, 16mn square tubes, 16mn seamless square tubes, stainless steel square tubes, hot-dipped galvanized square tubes, and other seamless steel pipe products. The specifications and sizes of square and rectangular tubes range from 20*20 to 600*600 for square tubes and 20*30 to 400*800 for rectangular tubes, with thicknesses from 0.6mm to 28mm, offering over 100 different specifications. Materials include Q235 square tubes, Q345 square tubes, 20#, 45#, seamless pipes, and alloy steel. Our company has 5 precision rolling production lines and can customize various seamless precision tubes and bright tubes according to customer requirements.